In this paper, we design, fabricate and characterize a new electromagnetically actuated variable-focus liquid lens which consists of two polymethyl methacrylate (PMMA) substrates, a SU-8 substrate, a polydimethylsiloxane (PDMS) membrane, a permanent magnet and a planar electromagnetic actuator. The performance of this liquid lens is tested from four aspects including surface profiling, optical observation, variation of focal length and dynamic response speed. The results shows that with increasing current, the optical chamber PDMS membrane bulges up into a shape with a smaller radius of curvature, and the picture recorded by a charge-coupled device (CCD) camera through the liquid lens also gradually becomes blurred. As the current changes from -1 to 1.2 A, the whole measured focal length of the proposed liquid lens ranges from -133 to -390 mm and from 389 to 61 mm. Then a 0.8 A square-wave current is applied to the electrode, and the actuation time and relaxation time are 340 and 460 ms, respectively. The liquid lens proposed in the paper is easily integrated with microfluidic chips and medical detecting instruments due to its planar structure.
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http://dx.doi.org/10.3390/mi7100190 | DOI Listing |
Health Phys
January 2025
Division of Vision Research for Environmental Health, Medical Research Institute and Department of Ophthalmology, Kanazawa Medical University, Kahoku, Japan.
Electromagnetic radiation energy at millimeter wave frequencies, typically 30 GHz to 300 GHz, is ubiquitously used in society in devices for telecommunications; radar and imaging systems for vehicle collision avoidance, security screening, and medical equipment; scientific research tools for spectroscopy; industrial applications for non-destructive testing and precise measurement; and military and defense applications. Understanding the biological effects of this technology is essential. We have been investigating ocular responses and damage thresholds comparing various frequencies using rabbit eyes and dedicated experimental apparatus.
View Article and Find Full Text PDFEye Contact Lens
December 2024
Department of Ophthalmology (H.T.), Juntendo University Shizuoka Hospital, Izunokuni, Japan; Department of Ophthalmology (A.M.), St. Marianna University School of Medicine, Kawasaki, Japan; Department of Innovative Visual Science (S.K.), Osaka University Graduate School of Medicine, Osaka, Japan; Department of Ophthalmology (Y.H.), Toho University Faculty of Medicine, Tokyo, Japan; and Japan Contact Lens Society (H.T., A.M., S.K., Y.H.), Osaka, Japan.
This review examines the history of contact lens (CL) care products, particularly focusing on hard contact lenses (HCLs) like those made from polymethyl methacrylate and rigid gas permeable (RGP) materials. Although literature on CL history is extensive, there is limited information on the history of CL care products, especially in Japan. This review uses advertisements from the Journal of the Japan Contact Lens Society from 1959 to 2023 to trace the evolution of these products.
View Article and Find Full Text PDFEye Contact Lens
November 2024
School of Optometry and Vision Science (K.E., F.S., B.T., J.C., B.G.), University of New South Wales, Sydney, Australia; and Department of Optics and Optometry and Vision Sciences (C.T.-E.), University of Valencia, Valencia, Spain.
Objectives: To assess the reliability of the liquid jet esthesiometer (LJA) for measurement of corneal sensitivity.
Methods: Two separate studies were conducted to assess intrasession repeatability (study 1) and intersession reproducibility (study 2) of corneal sensitivity measured using the LJA. Thirty participants (13 female and 17 male participants, age 23±6 years) participated in study 1 and another 30 (18 female and 12 male participants, 35±10 years) participated in study 2.
Small
January 2025
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China.
Phys Rev Lett
December 2024
Carlos III University of Madrid, Thermal and Fluids Engineering Department, Avenida de la Universidad, 30 (Sabatini building), 28911 Leganés (Madrid), Spain.
We present a surface analog to a dripping faucet, where a viscous liquid slides down an immiscible meniscus. Periodic pinch-off of the dripping filament is observed, generating a succession of monodisperse floating lenses. We show that this interfacial dripping faucet can be described analogously to its single-phase counterpart, replacing surface tension by the spreading coefficient, and even undergoes a transition to a jetting regime.
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